enjoyment of the dwelling for the sole purpose of noncommercial residential use, together with any structures necessary to the dwelling which are situated on the land so designated, or (ii) property developed for agricultural uses, together with any structures accessory thereto which were so used on or before January 1, 1975. I n determining when and to what extent a property is to be considered an "improved property", the Secretary shall take into consideration the manner of use of such buildings and lands prior to January 1, 1975, and shall designate such lands as are reasonably necessary for the continued enjoyment of the property in the same manner and to the same extent as existed prior to such date. (f) The owner of an improved property, as defined in this Act, on the date of its acquisition, as a condition of such acquisition, may retain for himself, his heirs and assigns, a right of use and occupancy of the improved property for noncommercial residential or agricultural purposes, as the case may be, for a definite term of not more than twentyfive years, or, in lieu thereof, for a term ending at the death of the owner or the death of his spouse, whichever is later. The owner shall elect the term to be reserved. Unless the property is wholly or partially donated, the Secretary shall pay to the owner the fair market value of the property on the date of its acquisition, less the fair market value on that date of the right retained by the owner. A right retained by the owner pursuant to this section shall be subject to termination by the Secretary upon his determination that it is being exercised in a manner inconsistent with the purposes of this Act, and it shall terminate by operation of law upon notification by the Secretary to the holder of the right of such determination and tendering to him the amount equal to the fair market value of that portion which remains unexpired. (g) I n exercising his authority to acquire property under this Act, the Secretary shall give prompt and careful consideration to any offer made by an individual owning property within the recreation area to sell such property, if such individual notifies the Secretary that the continued ownership of such property is causing, or would result in, undue hardship. SEC. 3. (a) Within one year after the date of the enactment of this Act, the Secretary shall submit, in writing, to the Committees on Interior and Insular Aft'airs and to the Committees on Appropriations of the United States Congress a detailed plan which shall indicate: (i) the lands and areas which he deems essential to the protection and public enjoyment of this recreation area, (ii) the lands which he has previously acquired by purchase, donation, exchange, or transfer for the purpose of this recreation area, and (iii) the annual acquisition program (including the level of funding) which he recommends for the ensuing five fiscal years, (b) I t is the express intent of the Congress that the Secretary should substantially complete the land acquisition program contemplated by this Act within six years after the date of its enactment.